Bascule bridge lock



p 16, 1952 H. H. GILBERT 2,610,341

BASCULE BRIDGE LOCK Filed Spt. 12,. 1949 s Sheets-Sheet} F1|E L IN VEN TOR. c/ H G/Yber'f (s Z 'ZAVQZQM;

Sept. 16, 1952 H. H. GILBERT BASCULE BRIDGE LOCK 3 Sheets-Sheet 2 Filed Sept. 12, 1949 m i e? Lu N ww m n Q I N w\ m o a o o Q Q E MN &

' INVENTOR. Hare/a H. ax/berf Patented Sept. 16, 195:

- 2,610,341 BAsoULE BRIDGE LOCK *namla 11. Gilbert, 'San Carlos; Calif. Application September 12, 1949, Serial No. 115,225

.Thisinvention relates to bridge locks and particularly to center-shear -1ocl s for double leaf bascule bridges.

Double leaf bascule bridges are well-known the civil engineering profession and their advanx V I Claiins. (01. 14-41) tagesrare well-known to those-skilled in the art.

However, and as is also well-known to those skilled in the art, :they are subject to certain shortcomings, one of the most important of which is the problem of providing a suitable center shear lock; to carry a live load such as a load imposed v by, amoving crane or train, or by vehicular traflic. "In the past double leaf bascule bridge shear. locks have consisted of a pair of shear pins which ranlongitudinally of the bridge. Certain mechanical difficulties were encountered as, for' example, the difficulty of aligning the two leaves of the bridge both vertically and horizontally. In addition, such devices provided only a single shear and required a substantial mass and crosssection to meet the strain and forces encountered in'bridges ofthis character.

-It-is an object of the present invention to provide a double leaf basculebridge centershear lock which will provide a doubleshear.

It is a further object of this invention to provide adevice of this characterwhich issimple to operate, which provides minimum clearance vertically about the shear pin and the face of the groove'receiving the same and which at the-same time presents maximum load bearing surfaces forthe transfer. of the load from one leaf ofthe bridge to the other. i

It is a further object of this invention to provide a double leaf bascule-bridge center shear lock which allows free movementof the leavesof the bridge longitudinally with respect to one another during expansion and contraction. i

It is afurther object of this invention toprovide a, free-floating aligning member. adapted to receive and accommodate'the shear lock pin in spite of any small differences of angular alignmentbetweenthe adjacent leaves of the bridge.

Other objects and advantages of the invention will appear from the following description taken in conjunction with the accompanying drawings inwhich: F

Figure '1 represents a plan view of, the adjacent ends of the'two leaves of a double leaf bascule bridge in which my invention is incorporated; one half width of the bridge is shown only, a

similar arrangement being provided on the otherhalf of the bridge;

Figure 2 represents a view of the end of the bascule leaf taken along the line 2+2 of Figure l g Figure 3 represents an enlarged cross section taken along the line 3 -1-3 of Figure 2; v Figure 4 represents a cross section taken along the line 44 of Figure 3;

Figure 5 represents a cross section taken along the line 5-5 of Figure 4; and

Figure 6 represents anexploded view of the device shown in Figure-3. I

As is shown generally in Figures joining leaves [0 and H of a bascule typev bridge join at their adjacent ends and are locked 'to-' gether'by a suitable device, in thiscase called a shear lock, to transfer the 'live load-shear fromone leaf to the other. 1

As is particularly shown. in Figurel, the leaf I0 of the double leaf bascule bridge illustrated. herein carries movable-lock pins l2 and their :op-

eratingmechanism, together withwhat might be termed the female or receiving member l3 of the leaf bascule bridge carries the male the locking mechanism."

The shear pin I2 consists generally of a pin,-

rectangular in cross section, as shown. As is shown in Figures 1", 2 and 4', pin I2 is provided "with a rounded end l6 and the other end is adapted to be secured'to a connecting-rod I! by' means of a suitable wrist pin arrangement l8. It

is, of course, understood that in the construction of particular bridges certain types of connecting elements may be desirable and may be utilized without departingfrom the spirit of this invention. I The pin I2 is adapted to'reciprocate within a slot or keyway 2| formed generally as shown in Figures8 and'6. l

The slot 2| is formed by a, recess in the casting 22 which in turn is suitably secured to the leaf Ill by means of bolts or by welding or any other suitable means as expediency may dictate. A cap 23, in the form of'a plate, is provided to over- "lie a portion of the slot in such a manneras to retain the pin [2 in the slot; The cross section In addition to the "horizontal recess 2|, the

casting 22 is provided with a vertical slot or channel 26 generally asshown in Figures 1, 2, 4 and 5. Asisshown in Figures 1, 2, 4 and 5 the yertical channelZfi is slightly flared atboth its upper and lower ends, but atthe point at which it intersects horizontal slot 2|, it is substantially the same width as the member [4.

The male member I4, as isparticula'rlyshown in Figures 1, 5 and 6, consists. generally of a cast- 1 and 2,' ad-- ing 28 Which may be suitably secured to the leaf I l of the double leaf bascule bridge herein described. The member l4ris adapted to be received within the vertical slot 26 in the member l3 and by virtue of the flared shape of the slot 26 is adapted to be centered therewithin when the leaves are in proper position for the reciprocation and actuation of the shear pin l2.

Casting; 28 is also provided with a horizontal circular recess 3| as shown. I have provided a pair of aligning discs 32 and 33 which are adapted to be accommodated within the recess 3!, and

4 same is centered with respect to said slot, and consequently to the leaf l of the double leaf bascule bridge. When the members l3 and I4 are substantially in the position shown in Figures 2 and 4, the electric motor 4| is again actuated and the crank wheels 44 are again rotated. Rotary motion of the crank wheels 44 will, at that time, cause the pin l2 to be moved to the left, as shown in Figures 1 and- 2. Because of the rotatable disc constructions fizsand 3:3 andbecause of the rounded end iii of the pin l2, the pin will be advanced through the slot 3|. The rotatable discs 32 and 33 will permit slight deflection, de-

' pending upon the relative sizes of the keyways and thus they become, in effect, one loosely: r0 1 tatably mounted member within the recess 31.. The discs 32 and 33 are provided with a common keyway 34 which is in substantial registry with a keyway- 33 in the casting 28, Thekeyways 34 and 3B loosely accommodate a key -31.- The key 3'! permits a slight rotation of the discs 32 and 33 within the circular recess 3!. This assembly prov-ides a floating alignment disc and allows a certain amount of deflection and adjustment for purposes to be more fully hereinafter described. The means for actuating the pin 12 consists generally of a motor 4| which, through identical drive shafts 42 and suitable gear reduction de-' vices 43-, operates a pair of crank wheels 44.

Connecting rods l1 are suitably secured to the crank Wheels 44 whereby, upon rotation of the crank wheels 44, reciprocating motion is transmitted to the pin [2 to either advance the same to the left; as shown in Figure 1, or advance the same to the right. A suitablelimit switch '45 is provided to permit only 180 rotation of the wheels 44.

At this 'pointit should be made clear that all of-th'e assembly to the left. of the. motor 4|; as

shown in Figures 1 and 2, is duplicated on the her sides orto the ri ht; of he motor. Mite rovide a pair of" pins 12' and their receiving lements Band l4. whereby suitable. lockingis pro vided a each side of: e ch of the leaves of the ouble bascule ridge herein described:

The motor M and the gear reduction unit 43 ay e of any pa lar ype which may be a vantesc w h r pect to he particular typ fscribed as follows: Let it be assumed, that both;

leave of the bridge are down and that traffic? is passing over the roadway Illa. Then; let it be assumed that it is desirable to raise the leaves It! and H of the bridge. The electric motor 4! isactuated and the crank wheels 44, are actuated one-halfa revolution. This rotary motion, of the crank wheels 44. is translated by the connecting rod H to the pin 12 .and the Same, is moved to her sh as shown in Figur s 1 and 2, in; ch a manner that it iswithdrawn entirely from the male portion I4, It must be borne in mind that similar action is simultaneously occurrin On the, other side of, the bridge. When this is done the i ge e t b rais d.- The bri ge s. then in the casting 22, the male member l4 will be urged into the position generally shown in Figures 2 and 4, that is, the position at which the Be-e. cause of the double flare of the vertical slot 26 34 and 36 and ,the key 31. At any rate, as the pin [6 is advanced through the slot 3|, the two discs 32;,arid 33 will be deflected slightly to accommodate themselves to the pin l2. The pin I2 will then be fartheradvanced through the slot 2 Lin the casting 2 2 and will beurged to the position shown-inl igures' 1, 2' and 4 and will pre vide a double she'anbetween the members l3 In addition, "the rotatablediscs 32 and 33 'will permit a pin "l2 to be received within the slot 3| when theadja'cent ends of the leaves of the bridge are either slightly above-or slightly below the horizontal. By this I mean that it is 'not'essen- ,tial that the two leaves of the bridge meet in a predetermined plane prior to their being locked together 'by the pin l2. The difference of a few It will be obvious from'the foregoing that I" have provided a suitable double shear pin construction which has numerous substantial advantages overpresent'types of construction.

In the first place I have provided a pin which in turn provides a double shearrather than a single shear'for a live load. 7 I j In the second place I have provided a female poi-tion whi'ch is outwardly-"flaring in both directions whereby regardless ofwhich leaf in or I I of the double leafbascule type bridge comes-dow'n" first, the other will center itself properly with respect thereto in avertical plane. In addition,"

I have provided a rotatable type of self-aligning disc construction upon the male member to allow for slight deflection and to prevent jamming of the pin upon operation of the pin should one' or the other ofthe members 13 or l4 be slightly out of perfect angular alignment.

I claim; I

In a device of the character described in which two iin'suppr irted load bearing members meet, a shear pin on one of said members adapted to be moved transversely with respect thereto, means for receiving said pin on said other member, said means for receiving said pin comprising a looselymounted member provided with a transverse slot.

2. In a bascule bridge construction, a pair of pivoted bridge members whose ends are adapted to meet whenithe bridge is in lowered position, a lock for said bridge members comprising apair of pins, each of said pins being slidably mounted arena of said members, a pair of spaced pin guide supports mounted on said member and receiving said pins when they are moved transsely with sp ct thereto; a pair of means onv the other member each of which, is adaptedto be p sitioned. a slot in one .of. said guide sup por s and. to. r ive oneof. said; pinssaid means including a pair of loosely mounted member's having a slot to receive said pins and adapted to accommodate themselves with respect to said pins when said pins are received therein.

3. In a device of the character described in which two unsupported load bearing members meet, means for locking said members against vertical movement comprising a slidable shear pin on one of said members and adapted to be moved transversely with respect thereto, a pair of spaced guide support members mounted on said one member and adapted to receive said pin, means for receiving said pin on said other member, said last-named means for receiving said pin comprising a loosely mounted member on said a second member provided with a slot which is adapted to accommodate said pin when said pin is moved into engagement with said guide support members.

4. In a device of the character described in which two unsupported load bearing members meet, means for locking said members together against vertical movement comprising a plurality of double shear pins slidably mounted on one of said members and adapted to be moved transversely with respect thereto, means for receiving each of said pins on said other member,

each of said means for receiving saidpins comprising a loosely mounted member on said second member provided with a slot which is adapted to accommodate said pins and which is open on the side adjacent said first named member.

5. In a double leaf bascule bridge construction, a center shear lock comprising a member fixed to the end of one of said leaves and slotted both vertically and horizontally, a second member fixed tothe end of the other of said leaves and slotted horizontally, said second member being adapted to be received within the vertical slot in said first member, a loosely mounted disc member carried by said second member and serving to adjustably define the positioning of the horizontal slot in said second member, and means for locking said members against vertical shearing movement including a shear pin movable into and out of engagement with the horizontal slot in said first member and said disc in a direction transversely of said bridge leaves.

. HAROLD H. GILBERT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 685,768 Keller Nov. 5, 1901 1,659,250 Erdal Feb. 14, 1928 

